Bio 152 Paper

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Pittala, Keerthana, Elly Ranum, Keighley Reisenauer

Lab 503, 407, 314

5/3/2013A META-ANALYSIS OF TREATMENTS FOR MYELODYSPLATIC SYNDROME

EVALUATING EFFECTIVENESS OF EPIGENETIC THERAPY, CHEMOTHERAPY,

AND BONE MARROW TRANSPLANT

PRELIMINARY ABSTRACT

Myelodysplastic syndrome (MDS) is a “pre-cancer” of the bone marrow that usually results in

Acute Myelogenous Leukemia (AML). These syndromes involve the degeneration of stem cells

in the bone marrow inducing irregular production of red blood cells. There are several possible

treatments, but the most successful target the genome or the location of cancer. We produced a

meta-analysis of thirty journals, 10 on each type of treatment, and focused on remission rates.

Several databases were used in accumulating data. We addressed the question: of epigenetic

therapy, chemotherapy, and bone marrow transplant, which treatment of MDS is the most

effective in terms of suppression? We concluded that bone marrow transplant was the most

effective treatment (as defined by the highest average score achieved by our index analysis).

INTRODUCTION

“Myelodysplastic syndromes (MDS) include a heterogeneous group of clonal myeloid

stem cell disorders characterized by peripheral cytopenias and dysplasia of bone marrow

progenitor cells” (Candelaria, 2010). Myelodysplastic syndrome is a highly complex disease that

has no known cure. Several treatments are available; among the most commonly used and

researched are epigenetic therapy, chemotherapy, and bone marrow transplant. However, no

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study has been found that evaluates the effectiveness of each type of these treatments as

compared to each other.

Epigenetic Therapy (Reisenauer)

“Epigenetic mechanisms that can dysregulate gene expression have become increasingly

attractive as potential targets in the therapy of human cancer” (Maslak, 2006). To determine the

best treatment and regimen, a multitude of drugs and treatment regimens have been assayed. An

overall assessment has been achieved that a combination therapy of low dosages and high

intensities will result in the most remissions. “Strategies of combining different drugs aim at

increasing the efficacy of the single agents, therefore improving response rates, prolonging

response duration, and decreasing the toxicities associated with the treatment” (Follo, 2011)

Epigenetic therapy trials define the outcomes of their study in terms of complete remission (CR),

partial remission (PR), and other defined levels of symptom suppression.

Chemotherapy (Ranum)

Lenalidomide has proven to be a promising drug for the treatment of patients with

Myelodysplastic Syndrome. This drug was chosen for this analysis as it is the most widely used

and researched, when compared to other chemotherapy drug regimens. The drug is especially

effective in patients exhibiting a genetic abnormality called 5q syndrome and leads to transfusion

independence in over two thirds of these patients (Ades, 2008). The drug is given in different

amounts and phases depending on the patient. The exact function of Lenalidomide is unknown,

however, as an immunomodulatory agent, it is believed to have several broad biological effects.

The drug can stimulate the immune system by enhancing the response of Cytotoxic T Cells and

Helper T Cells. It is also believed that the drug can slow the growth of blood vessels to prevent

rapid tumor growth (Rami 2011).

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Bone Marrow/Stem Cell Transplant (Pittala)

Clinical trials show that the effects of Bone Marrow transplants depend on the source,

relatives or an outside source, and the progression of the disease (Anderson, 1993). MDS that has

progressed to serious levels should not respond as actively to Bone Marrow/ Stem Cell

transplants; this progression also depends on the age of patients as the age of contraction and

years with disease influence the treatment type and overall effectiveness (Chunkang, 2007).

The effectiveness of Bone Marrow Transplants, Chemotherapy, and Epigenetic Therapy

is variable. There is no one treatment that has been labeled as the best or most effective method,

as based on our initial literature review; however, by comparing data from additional studies we

can hope to deduce the most effective treatment for patients with MDS. More formally, our

hypothesis is that there is no strong difference between epigenetic therapy, chemotherapy, and

bone marrow transplant in the treatment of MDS. The remainder of this paper will explore this

hypothesis by first describing the methods we used in gathering and analyzing our data. The

results section will highlight our findings; the discussion section will develop the implications of

this data and also explain any shortcomings of the study. The conclusion will recap the findings

and overall process of this study.

METHODS

In completing this meta-analysis, databases were searched using key terms and filtering

techniques. The relevant articles were compared within each treatment type and then cross-

analyzed to determine overall effectiveness. A scale and index (Appendix, Table 2) were

established to analyze success.

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Epigenetic Therapy

Using PubMed and Web of Knowledge databases to search for information, the key

terms “epigen*”, “MDS”, “Myelodysplastic syndrome”, and “therapy” were searched. Articles

written in English or translated into English were used. Subjects must have a median age over 55

years, no interfering health problems, and be classified with MDS or acute myelogenous

leukemia (AML). The studies must be clinical trials and published after 2000. They must also

report their results in terms of remission or symptom suppression. MDS is most common in older

patients and other interfering health problems could be inadequately accounted in the study, so

these studies were ruled out. Clinical trials were chosen because the focus was on recent work

being applied in a realistic setting to accurately trace the effectiveness of each treatment in “real

time.” No common drug was chosen because the variance between each study was too high.

Studies were excluded if the average age of subjects was below the selected age or if the study

was not conducted on humans. Also, the full article must be available (See Figure 1.3). The type

of trial, subject information, method controls and measurements, and results were recorded in a

table using headers to organize data (see Table 1). Overall, in these studies, CR is defined as

disease stabilization with successful methylation of the targeted gene. PR is considered no

regression or advancement of MDS or AML but without achieving complete stabilization or

remission. Null patients were unable to complete the full treatment regimen due to early death or

alternative complications.

Chemotherapy

Using Medline, Google Scholar, and Web of Knowledge as resources, several articles

were identified relating to the treatment of Myelodysplastic Syndrome using a chemotherapy

regimen of Lenalidomide. The databases were searched using the keywords “Myelodysplastic

Syndrome,” “MDS,” “Lenalidomide,” “chemotherapy,” and “treatment.” Studies that were

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written in English or translated into English were considered. Because MDS is most commonly

diagnosed in older patients, studies were only considered if they had a median age of at least 60

years old. Studies also needed to have been published in the last 20 years to ensure that the

findings and experimental methods are recent. The studies must involve the use of Lenalidomide

for the treatment of transfusion dependent adults with MDS, and report their results in terms of

treatment independence and/or erythroid response in patients. Studies were excluded if patients

were treated with more than one drug or therapy during their chemotherapy regimen. If the full

article was not available, the study was not considered. The selected articles’ authors’ names,

date of publication, age, sex, and health status of the patients, as well as results of the trials

including erythroid and cytogenic response, were recorded. The citing articles and citations of

related articles were also considered (See Figure 2.3). The information from all the articles was

then organized into an Excel spreadsheet (Table 1).

Bone Marrow/Stem Cell Transplant

Using Pubmed and Google Scholar, articles were found that related to MDS treatment

with Bone Marrow transplants. Data from clinical trials was preferred for the best analysis of a

treatment but retrospective studies provided greater insight into the long-term effects of a

treatment. Retrospective studies took patients from a single location that had undergone Stem

Cell or Bone Marrow transplants and compared their current state to their state during treatment

within a set time span. These studies consisted of patients who had previously received treatment

for MDS but did not benefit from it. Subjects of the studies aged from 3 years to 70+ years, no

age groups were specifically excluded so that the impact of age on treatment could be analyzed.

Articles were compiled using the keywords: “MDS”, “Bone Marrow transplants”, “Acute

Myelogenous Leukemia”, and “suppression”. The articles were then limited to studies done

within the past five years, except for one article which proved to be a basic study done on the

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subject and was cited by many current studies (Anderson, 1993 ). The data from the articles

collected was then compiled on Excel (Table 1). Data that was recorded included: author, year of

publication, duration of treatment, number of subjects and characteristics, methods and control of

the studies, method of measurement whether statistical or numerical, and the final results. Even

though the fields used for finding articles and studies was very broad this allows for a

consideration of a select few characteristics in patients that are addressed and therefore allow for

a better analysis of the effectiveness of this treatment on certain groups of people. Studies

involving Bone Marrow transplants, including allogeneic bone marrow transplants, and

Hematopoietic cell transplantation were selected. Age of the subjects of the studies was not used

to separate studies (See Figure 3.3). Chance and rate of relapse and overall success of

suppression were used to compare the different treatments.

To compare all these studies between treatments, both an independent scale and an

overarching index analysis were introduced. In the scale, complete remission (CR) consists of

patients who did not relapse within the timeframe of the study and became independent of

regular treatment; partial remission (PR) achieves similar results as CR, but still requires a

degree of treatment continuation and these patients do not fully achieve “success” as defined by

the study; failure to complete the study in full, early death, or placebo treatment is defined as

null. For epigenetic treatment, CR is defined as disease stabilization with successful methylation

of the targeted gene; PR is defined as no regression or advancement of MDS or AML, but

without achieving complete stabilization or remission; null is defined as patients who were

unable to complete the full treatment regimen due to early death or alternative complications. For

chemotherapy, CR is defined as transfusion independence , PR is defined as a reduction in the

number of transfusions needed monthly by at least half , and null is defined as patients who did

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not complete the treatment regimen or were taking a placebo. For bone marrow transplant, CR is

defined as being disease-free and without relapse within the time frame of the study, PR is

defined as relapse, and null is defined as death directly caused by treatment (not due to relapse)

and includes subjects that could not be used for analysis of partial remissions.

The index was established as a means to compare several variables across each study and

reach numeric conclusions of effectiveness of treatment. Each study was analyzed on length of

trial, number of participants, the percentage of participants showing any positive effects out of

total number of participants, and the percentage of participants showing CR, PR, and Null, again,

out of the total number of participants. A numeric value range was set up for each category

mentioned. A particular study received a number score for each of these variables. The first three

columns give a baseline numeric value to each individual study. From there, studies were given

three separate scores based on the three outcome categories’ (CR, PR, and Null) percentage of

patients that fell within each type of category, respectively. To stratify this data and put more

emphasis on effectiveness, the scale was re-introduced and a value 10 (CR), 5 (PR), or 0 (Null)

was added to each respective group. The total score for each study was, thus, comprised of a

series of three numbers that numerically evaluated the effectiveness of the trial (See Table 2).

The average score for each treatment type was then calculated and used as a comparison between

the studies.

RESULTS

In a cross-study of all the articles between treatment types, no consistent measurement of

treatment success existed. To diminish this, an encompassing definition of symptom suppression

was defined. For our purposes, treatment success was defined as independence from continual

treatment for a length of time and a reduction in cancerous symptoms.

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Epigenetic Therapy

10 journals were identified as viable epigenetic treatment clinical trial studies of MDS.

Between these ten, 345 patients were identified, all with diagnosed MDS or AML, the secondary

disease to MDS. In these studies, CR is defined as disease stabilization with successful

methylation of the targeted gene. PR is considered no regression or advancement of MDS or

acute myelogenous leukemia (AML), but without achieving complete stabilization or remission.

Null patients were unable to complete the full treatment regimen due to early death or alternative

complications.

Overall, of the 345 patients analyzed, 24% of patients were CR, 47% were PR, and 29%

were null for epigenetic therapy (see Figure 1.1). The average index score for epigenetic

treatment was calculated to be 40.8 (Table 2).

Chemotherapy

10 studies were identified studying the use of Lenalidomide to treat MDS involving a

total of 867 human participants. Transfusion independence is considered to be complete

remission (CR) and a decrease in the number of transfusion needed monthly by at least half is

considered partial remissions(PR). Participants who were taking a placebo or who did not

complete the drug regimen are considered null.

Overall, 336(39%) participants achieved CR, 106(12%) achieved PR and 425(49%) were

considered null(see figure 2.1). The average index score for chemotherapy was 47.9 (see figure

2.2).

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The result of allogeneic bone marrow transplants must be observed over the course of

months or years; therefore, most studies were retrospective studies. These studies took patients

who had received bone marrow or stem cell transplants within a certain time frame from a

specific hospital or clinic and followed their progress. The cause of death, rate of relapse, and

disease-free survival are the main topics of interest. The results vary and patients relapsed

depending on the initial severity of MDS. Clinical trials show that the effects of Bone Marrow

transplants depend on the source, relatives or an outside source, and the progression of the

disease (Zimmerman, 2011). MDS that has progressed to serious levels should not respond as

actively to Bone Marrow/ Stem Cell transplants; this progression also depends on the age of

patients as the age of contraction and years with disease influence the treatment type and overall

effectiveness. The levels of red blood cells, neutrophils, and platelets are monitored to measure

the effects of transplants. It was found that allogeneic bone marrow transplants were successful

for individuals with MDS who were under the age of 40; however, the severity of MDS was a

significant determining factor of the effectiveness of treatment (Anderson, 1993). Some younger

patients benefited from treatment but those suffering from MDS, which was a result of

chemotherapy or radiotherapy for cancer, usually resulted in long-term freedom from disease

(Kröger, 2007). This fact was said to be related to the amount of proliferation of MDS before the

time of treatment. Younger patients who received treatment sooner limited the amount of

proliferation making the effects of the treatment more significant. Older patients who had

received treatment were studied, red blood cell count and neutrophil counts were taken, and

various treatments were used to determine the effectiveness of treatment. Many older patients

died because of relapse (Khabori, 2011). Older patients who participated in studies tended to

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have received previous treatment for MDS including chemotherapy or radiotherapy (Spina,

2012). These patients usually did not respond positively to bone marrow/stem cell transplants

because their condition was worse off compared to younger patients. This showed that bone

marrow transplants and stem cell transplants were helpful in the short term but could not

guarantee the complete prevention of relapse or disease-free survival (Lukenbill, 2013). A

significant portion of patients who underwent treatment relapsed and died about 3-10 years after

treatment due to causes directly related to treatment or because of other adverse causes.

Final Conclusion of Results

For epigenetic therapy 83 (24%) were CR, 162 (47%) PR, and 100 (29%) null. For

chemotherapy, 336(39%) were CR, 106(12%) PR, and 425(49%) null. For bone marrow 572

(34.31%) were CR, 477 (28.61%) PR, and 618 (37.07%) null. Based on these results alone

chemotherapy had the highest percentage of CR patients from score-only analysis. Bone

Marrow/Stem cell transplants had the highest average index score at 56, compared to the other

two treatments, and thusly was deemed the most effective treatment of myelodysplastic

syndrome.

DISCUSSION

In comparing these three treatments, chemotherapy, bone marrow transplant, and

epigenetic treatment, it was concluded that chemotherapy has the highest percentage of patients

who reach CR, but bone marrow transplant has the highest average index score. However, this

comparison is not without error. Each type of treatment focuses on a distinct symptom and

attacks a highly specific cause of MDS. Also, the methods used to study effectiveness and the

metric used to measure progress varied between treatments. For this reason, an overarching scale

and analytical index had to be defined and some of the specific variants of each study were lost.

Also, in order to truly understand which treatment is the most effective, other factors must be

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taken into account. More research and analysis must be done on the relative safety of the

treatments including what, if any, adverse effects occur during and after treatment. How often

adverse events occur and their severity should also be taken into account. Another important

factor that should be considered is the length of time that a patient remains in remission. MDS

does not have a known cure at this time. As a result, all patients will eventually relapse.

However, the length of time that they remain healthy or treatment independent is also a factor

that changes the effectiveness of a treatment.

Epigenetic Therapy

It is important to note that the indexical analysis of the epigenetic therapy trials is

imperfect. Although this is an efficient and partially reliable means of assessment, this index

does not completely account for all the nuances of each trial. The largest concern is with trials

that do not produce results for a certain scale value, especially CR values. Because the scale is

designed to stratify data, large gaps are used to create distinct separations between the most and

least effective outcomes: CR and null, respectively. If a study does not achieve any CR patients,

a large-scale value is still added to this score and the indexical CR score for that particular study

is deceivingly high. Furthermore, the Follo 2011 Study mentioned “10 healthy, normal

volunteers” that were included in the patient group. However, because these patients’ exact

involvement was not described, only the 20 MDS patients whose treatments were outlined in the

article were included.

Chemotherapy

The comparison of each chemotherapy study to other chemotherapy studies is

unsatisfactory. Though the studies all involve the use of the same drug, Lenalidomide, they vary

in their dosage and treatment schedule. Furthermore, the comparison of chemotherapy to bone

marrow transplant and epigenetic studies is flawed. All the studies use a different metric to

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measure success. Though the creation of the index helps to compare the studies, it cannot

account for all of the differences between studies.

Bone Marrow/Stem Cell Transplants

Comparing studies that vary in methods, drug concentrations and length of treatment

does not yield perfectly accurate results. There are many discrepancies that must be taken into

account when compiling data and comparing results of studies. The results of some studies

contradicted each other when stating that bone marrow or stem cells were beneficial to the

recipient while other studies stated that treatment was not significant. Statistical measures also

varied from study to study so comparing result was not as accurate.

CONCLUSION

In conclusion, our hypothesis is that there is no significant difference between epigenetic

therapy, chemotherapy, and bone marrow transplant in the treatment of MDS. This paper

explored this hypothesis by first describing the methods we used in gathering and analyzing our

data. The results section highlighted our findings; the discussion section developed the

implications of this data and also any shortcomings of the study. Based on percentages of CR

and the results of our index, Bone Marrow Transplant appears to be the most promising

treatment for MDS among the three treatments studied.

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REFERENCES

Excel sheet attached in Appendix (Table 1)

Abouyahya et al. 2011, Treatment with Lenalidomide in Myelodysplastic Syndromes with 5q Deletion; Results From the Patient Named Program (PNP) in the Netherlands.

Ades, et al. 2008, Efficacy and safety of lenalidomide in intermediate-2 or high-risk myelodysplastic syndromes with 5q deletion: results of a phase 2 study.

Anderson, et al. 1993, Allogeneic bone marrow transplantation for 93 patients with myelodysplastic syndrome.

Candelaria, Myrna et. al. 2010, Hydralazine and magnesium valproate as epigenetic treatment for myelodysplastic syndrome. Preliminary results of a phase-II trial.

Chunkang, et al. 2007, Hematopoietic cell transplantation in patients with myelodysplastic syndrome or acute myeloid leukemia arising from myelodysplastic syndrome: similar outcomes in patients with de novo disease and disease following prior therapy or antecedent hematologic disorders.

Claus, Rainer et. al, 2013, Decitabine induces very early in vivo DNA methylation changes in blasts from patients with acute myeloid leukemia.

Fandy, Tamer E. et, al, 2009, Early epigenetic changes and DNA damage do not predict clinical response in an overlapping schedule of 5-azacytidine and entinostat in patients with myeloid malignancies.

Fenaux, et al. 2011, A randomized phase 3 study of lenalidomide versus placebo in RBC transfusion-dependent patients with Low-/Intermediate-1-risk myelodysplastic syndromes with del5q.

Follo, M Y, et. al, 2011, Myelodysplasias: Synergistic induction of PI-PLCβ1 signaling by azacitidine and valproic acid in high-risk myelodysplastic syndromes.

Ho, et al. 2004, Reduced-intensity allogeneic hematopoietic stem cell transplantation for myelodysplastic syndrome and acute myeloid leukemia with multilineage dysplasia using fludarabine, busulphan, and alemtuzumab (FBC) conditioning.

Kantarjian, Hagop et. al. 2007, Results of a randomized study of 3 schedules of low-dose decitabine in higher-risk myelodysplastic syndrome and chronic myelomonocytic leukemia.

Khabori, et al, 2011, Impact of intensity of conditioning therapy in patients aged 40-60 years with AML/myelodysplastic syndrome undergoing allogeneic transplantation.

Klimek, Virginia M. et. al. 2008, Tolerability, Pharmacodynamics, and Pharmacokinetics Studies of Depsipeptide (Romidepsin) in Patients with Acute Myelogenous Leukemia or Advanced Myelodysplastic Syndromes.

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Klisovic, Rebecca B. et. al. 2008, A Phase I Biological Study of MG98, an Oligodeoxynucleotide Antisense to DNA Methyltransferase 1, in Patients with High-Risk Myelodysplasia and Acute Myeloid Leukemia.

Kröger, et al. 2007, Autologous stem cell transplantation for therapy-related acute myeloid leukemia and myelodysplastic syndrome.

Le Bras, et al. 2011, Treatment by Lenalidomide in lower risk myelodysplastic syndrome with 5q deletion—The GFM experience.

List, et al. 2005, Efficacy of Lenalidomide in Myelodysplastic Syndromes.

List, et al. 2006, Lenalidomide in the Myelodysplastic Syndrome with Chromosome 5q Deletion.

Litzow, et al. 2010, Allogeneic transplantation for therapy-related myelodysplastic syndrome and acute myeloid leukemia.

Lukenbill, et al. 2013, Defining Incidence, Risk Factors, and Impact on Survival of Central Line-Associated Blood Stream Infections Following Hematopoietic Cell Transplantation in Acute Myeloid Leukemia and Myelodysplastic Syndrome.

Majhail, et al. 2012, Reduced-intensity hematopoietic cell transplantation in older patients with AML/MDS: umbilical cord blood is a feasible option for patients without HLA-matched sibling donors.

Maslak, P, et. all, 2006, Pilot study of combination transcriptional modulation therapy with sodium phenylbutyrate and 5-azacytidine in patients with acute myeloid leukemia or myelodysplastic syndrome.

Olivia et al. 2009 Lenalidomide for the Treatment of Low- and Int-1-Risk MDS with Del(5q): Efficacy and Quality of Life Study.

Olivia et al. 2013 Lenalidomide in Low-and Intermediate-1 IPSS risk myelodysplastic syndromes with del(5q): an Italian phase II trial of health-related quality of life, safety, and efficacy.

Potapova, Anna et. al. 2009, Epigenetic inactivation of tumour suppressor gene KLF11 in myelodysplastic syndromes.

Raza, et al. 2007, Phase 2 study of lenalidomide in transfusion-dependent, low-risk, and intermediate-1–risk myelodysplastic syndromes with karyotypes other than deletion 5q.

Sibon, et al. 2011, Lenalidomide in lower-risk myelodysplastic syndromes with karyotypes other than deletion 5q and refractory to erythropoiesis-stimulating agents.

Spina, et al. 2012, Allogeneic stem cell transplantation in therapy-related acute myeloid leukemia and myelodysplastic syndromes: impact of patient characteristics and timing of transplant.

Stresemann, Carlo et. al. 2008, Azacytidine causes complex DNA methylation responses in myeloid leukemia.

Zimmerman, et al. 2011, Allogeneic hematopoietic cell transplantation in patients with myelodysplastic syndrome and concurrent lymphoid malignancy.

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FIGURES AND TABLES

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Figure 3.1: This graph shows the percentage of patients from each study that achieved CR, PR, and Null.

Figure 3.2: This graph shows the index scores of CR, PR and Null for each trial.

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Figure 1.3: This flowchart depicts the online search process for eliminating and selecting various

articles specific to epigenetic treatment.

Articles rejected for relevance after review of Abstract

Articles Used:

n = 10

Excluded Articles:

(n = 9) Restriction 1

(n = 142) Restriction 2

Refined Search Results

n = 210


n = 68

Restriction 2 : Clinical Trials, Article

Restriction 1 : English, Published before 2000

Duplicates Removed

n = 0

Unduplicated Results

n = 219

Search Results (219)

PubMed (123)

Web of Knowledge (96)

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Figure 2.3: This flowchart depicts the online search process for eliminating and selecting various articles specific to chemotherapy.

Restriction 2 : Report results in terms of erythroid

response

Articles Used:

10

Excluded Articles:

2 were not available in full text

2

Articles found through citations


10


70

Relevant Articles

25

Irrelevant Articles

45

Chemotherapy

Restriction 1: Non-primary sources were excluded

Duplicates Removed

25


91


Medline (41)

Google Scholar (39)


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Figure 3.3: This flowchart depicts the online search process for eliminating and selecting various

articles specific to bone marrow transplant.

Restriction 2:

Full text available, relevant bone marrow-based

transplants

Articles Used:

n = 10

Excluded Articles:

(n = 6) Drug-based treatment

n = 2

Articles found through citations


n = 14


n = 37

Relevant Articles

n = 17

Irrelevant Articles

n = 20


Restriction 1:

Articles published in past 5 years, Clinical trials, Human

subjects

Duplicates Removed

n = 6


n = 3204


Pubmed (3201)


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APPENDIX

Documents

Bio 152 Paper